Intermediate Algebra (12th Edition)

$z=\{ ...,-2,-1,0,1,2,3,4 \}$
Integers are the negative, zero, and positive numbers which include $\{...,-3,-2,-1,0,1,2,3...\}$. Hence, the integers, $z$, less than or equal to $4$ are \begin{array}{l}\require{cancel} z=\{ ...,-2,-1,0,1,2,3,4 \} .\end{array}